Aircraft flight and performance parameters are monitored and recorded for various reasons and purposes. Two specific purposes, which are addressed by this invention, are the recording of primary flight parameters for retrieval and analysis in the event of an aircraft mishap or crash and the recording and analysis of various aircraft flight and performance parameters to assist in aircraft maintenance and to monitor both aircraft and crew performance.
In the prior art, the systematic monitoring and recording of primary flight parameters for retrieval and analysis in the event of an aircraft mishap or crash takes several forms. With respect to transport aircraft that are operated for commercial purposes, primary flight parameters that are useful in determining the cause of an aircraft mishap or crash initially were recorded in analog form by a flight data recorder that utilized a moving band of metal foil. In such a device, indentations are formed in the metal foil to indicate the value of each recorded parameter as a function of time. Generally, because of standards set by various regulatory agencies and commercial aviation trade associations, this type of flight data recorder provided a record of five flight parameters, including indicated air speed, altitude, vertical acceleration, heading and time. As the related arts advanced, flight data recorders were developed wherein the monitored analog signals are converted to a digital signal format and recorded on magnetic tape, instead of metal foil. Although such digital flight data recorders have specific advantages over prior art foil-type flight data recorders, the various regulatory agencies did not require the replacement of foil-type flight data recorders, mandating only that digital flight data recorders be utilized on aircraft that were certified for commercial use after a certain date. For example, in the United States, foil-type flight data recorders may still be utilized on each type of aircraft that was certified prior to September 1969 relative to usage in carrying passengers. Since various air frame manufacturers have periodically introduced new versions of such aircraft and because of the cost involved in replacing foil-type flight data recorders with digital flight data recorders, a significant portion of the aircraft employed by commercial carriers still employ foil-type data recorders.
Additional advances in the related technical arts have motivated both industry initiated and mandatory advances in the design and construction of digital flight data recorders. In this regard, through regulatory action and standardization efforts of various air carrier organizations, digital flight data recorder systems have been made available that record more than the above discussed five primary flight parameters. For example, in the United States and other countries, it is mandatory that each type of passenger carrying aircraft that was certified after September 1969 be equipped with a digital flight data recorder capable of recording at least sixteen parameters.
As a result of the above discussed evolution of flight data recorder technology and the issuance of various mandatory requirements, aircraft in current operation utilize a mixture of the various types of prior art flight data recorder systems. This presents several disadvantages and drawbacks. Firstly, in many cases it has not been economically feasible for the air carriers to replace the older types of flight data recorders with flight data recording systems that are capable of monitoring and recording at least 16 flight parameters. Since many air carriers operate numerous types of aircraft, it has been necessary that such air carries maintain and service various types of flight data recorder systems. Secondly, because the prior art has not provided a cost effective solution to equipping all aircraft with flight data recorders that monitor and record at least sixteen flight data parameters, regulatory agencies and air carrier associations have not required replacement of older type flight data recorders. However, the need and desire for improved aircraft accident investigation aids has resulted in recommendations by various U.S. and international organizations and agencies that would make replacement of older type flight data recorders mandatory.
Advances in the flight data recording arts and concomitant advances in the data processing arts has resulted in growing interest in collecting and analyzing various aircraft flight and performance parameters to assist both in aircraft maintenance and to monitor aircraft and crew performance. The objectives of such monitoring and analysis vary somewhat between the various air carriers and other interested parties and range from simply maintaining an extensive record of the recorded flight parameters for use in the event of an aircraft mishap or crash to comprehensive analysis of the data to provide short term and/or long term maintenance and logistic planning activities. As is known in the art, if economically feasible, the collection and analysis of such data can be extremely beneficial in both short term and long term aircraft maintenance and planning. For example, if the recorded data can be rapidly analyzed and made available to flight line maintenance personnel, the time required to identify and replace a faulty component can be substantially reduced to therby prevent or minimize disruptions in aircraft departure and arrival schedules. In the longer term, such monitoring and analysis can be useful in identifying gradual deterioration of an aircraft system or component, thereby permitting repair or replacement at a time that is both convenient and prior to actual failure. In addition, both the short term and long term monitoring and analysis of various flight parameters can be useful to flight crews and the carriers relative to establishing and executing flight procedures that result in reduced fuel consumption. Even further, such monitoring and analysis can yield information as to whether established procedures are resulting in the expected aircraft performance and efficiency and whether the flight crew is implementing a desired procedure.
Systems for collecting and analyzing flight data parameters to assist in aircraft maintenance and to monitor aircraft and crew performance are generically referred to airborne integrated data systems ("AIDS") and have taken various forms. various forms. In this regard, the simplest system basically includes a recorder that records each flight parameter recorded by the aircraft digital flight data recorder system. In this type of system, the flight data information is recorded on a magnetic tape that is periodically removed and sent to a ground based data processing station for subsequent computer analysis. In other somewhat more complex systems, provision is made for recording various flight parameters that are not collected by the aircraft digital flight data recorder. In some of these more complex arrangements, a data management unit and flight deck printer are provided. The data management unit permits the flight crew to selectively and intermittently activate the integrated data system during relevant portions of a flight or whenever a problem is suspected. Although the use of data management units eliminates or minimizes the recording of irrelevant data, successful system operation becomes dependent upon the flight crews ability to operate the system. In some situations, tending to higher priority tasks can prevent the flight crew from executing the procedures necessary to record relevant data information. Further, although inclusion of a flight deck printer can provide flight line personnel with timely data that is relevant to aircraft maintenance and repair procedures, currently available systems do not provide such data in a readily usable form.
Each above discussed implementation of an airborne integrated data system has distinct disadvantages and drawbacks. In this regard, systems that simply duplicate the information recorded by the flight data recorder system and those that simply record additional flight parameters do not provide data that can be utilized by flight line personnel. On the other hand, the more complex implementations of an airborne integrated data system are relatively expensive and are relatively heavy. Thus, although aircarriers recognize the benefits of such systems, the general attitude has been that the benefits are outweighed by the costs and weight penalties involved. Further wide spread use of airborne integrated data systems has been impeded because such systems generally must be specifically configured for each type of aircraft and, in many cases, for configuration variations within a particular type of aircraft. It is not unusual for a particular air carrier to operate various types of aircraft and to equip any given type of aircraft with various alternative systems and components. The airborne integrated data systems that have been proposed by the prior art are not readily adaptable to the various types of aircraft and alternative system configurations utilized in such aircraft, thereby further complicating the situation.